I'm just now getting into Crisis on Sarapin, Pt. 2 and am wanting to use the artillery. However, I'm not quite sure how to do it.

I know that I need a spotter, and I've actually set it up where I send in a Probot as spotter for the artillery. Then I got distracted as my base was attacked AND my attack force encountered resistence at the Rebel's airstrip. So, I was never able to actually find out if my artillery destroyed anything.

I guess what I need to know is:

How far away can the artillery be and still be effective? Can I leave the artillery at my primary base and send a spotter all the way to the airstrip and have it bombed? Or do I have to move the artillery closer. It would seem to be easier to leave it at my base and protect it heavily there rather than moving it closer to the front lines.